Earphone recording system



Feb. 29, 1944. l H 5 HELLER 2,342,667

EARPHONE RECORDING SYSTEM Filed Jan. 24, 1941 2 Sheets-Sheet l Feb. 29, 1944. H, s, HELLER 2,342,667

EARPHONE RECORDING SYSTEM Filed Jan. 24, 1941 2 Sheets-Sheet 2 Patented Feb. 29, 1944 Herman S. Heller, West Los Angeles, Calif.

. Application January 24, 1941*, Serial No. 375,807

15 Claims.

This invention relates to radio receiving systems, particularly in situations wherein the operator is furnished withradio head phones, and wherein a recording is made oi received signals, the general purpose and accomplishment of th e invention being the provision of means for indicating on such a record any period or periods during which the head phones are not worn by the operator.

The invention is generally designed for application in such situations as aircraft service, in which lt is highly important that one or more radio operators be constantly on watch, and in which it is highly important that any failure on the part oi' the operatoror operators be made known to supervisory authorities.

The present invention meets this need by the I provision of means for recording on the record medium, along with the incoming communication signal, a current wave of predetermined frequency or other distinguishable character. This indication current is produced and recorded at all times that the head phones are not being worn. When the head phones are positioned on the head of the operator, however, a switch associated with the phones is automatically actuated to stop the recording of the indication current, so'that only the received communication signal is then recorded. Subsequent analysis of the record reveals whether or not the operator was listening during the reception of, for example, instructions transmitted from the control station. As it is common in aircraft service to have more than one individual on listening duty simultaneously, for

instance, the pilot and co-pilct, or pilot and radio 1 operator, the invention provides means for producing ,one characteristic current wave for each head phone set, which is recorded along with the received communication signal when the head phones are not being worn, with switching means in association with each head phone set for interrupting the recording ofthe corresponding current wave when that set is on the head oi the operator. The resulting record discloses whether either or both of the operators was on duty at any given time, and allows responsibilities to be accurately placed.

The invention will be understood from the iollowing detailed description of certain selected illustrative embodiments thereof, reference for this purpose being had to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of one illustrative system in accordance with the invention;

Fig. 2 is a modification of Fi g. l;

\ Fig. 3 is a diagrammatic plan view of a porg tion of the recording tape and recording magnets of the form of the invention of Fig. 2;

Fig. 4 shows a further modiiied form oi the invention;

Fig. 5 is a sectional view of an earphone device in accordance with the invention, the section bej ing taken in accordance with line 5 5 of Fig. 6;

Fig. 6 is a section taken on line Ii-i of Fig. 5:

Fig. l is a, perspective of a contact device used in the earphone;

Fig. 8 is a view similar to Fig. 5, but showing a modification, the section of Fig. 8 being on Aline 3 8 of Fig. 9; and l' Fig. 9 is a section taken on line 8-3 of Fig. 8.'

The illustrative forms of the invention con'- template two sets of head phones, one for the pilot and one for the co-pilot or radio' operator. It is to be understood, however, that this is not limitative on the invention, since one head phone set or any greater number may be provided, as Y will be evident.

In Fig. 1 of the drawings, two head phone setsv IIJ and il are indicated, each comprising a pair of earphones I2. Numeral I3 designates a radio receiving set, to the output terminals of which*v are connected leads I5 and I8 going to recorder cation signal currents delivered from receiver I3 to leads I5 and I6.

Head phone sets III and Il are connected by leads 25 and 26, respectively, to communication signal lead I5 and by leads 2l and 28 to the stationary contact arms 29 and 3B of relays R1 and Rn, respectively. The other communication si'g-` nal lead I5 is connected by leads 30 and 3| to the intermediate, movable spring contact arms 32 and 33 of relays R1 and R2, respectively. I Contact arms 32 and 33 normally make with stationary contact arms 34 and 35, respectively. 'I'he relays R1 and Rz have electromagnets 36 and '31, respectively, which when energized move the intermediate spring contact arms 32rv and 33 out of contact with arms 34 and 35, and into contact with arms 29 and 30, respectively. Thus energization of magnet 36 connects head phones i0, across communication signal circuit I5, I6, and energization oi magnet 3l connects head phones II across circuit I5. I6. i

Magnets ll and 31 are energized through switches Si and Sz contained in head phone sets Il and II, which switches are automatically closed as the head phones are positioned on the head of the operator. Suitable automatically operated switch means are embodied in the head phone devices shown in Figs. to 9, and will be described in detail hereinafter. A source of current for magnets and 31 is indicated at 40. Leads Il connect one side of this source of current to head phone switch contacts Il, and the cooperating head phone switch contacts ll are connected by leads Il to the magnets $6 and 31. Return leads 4l from magnets Il and 31 are connected to the other side of current source lil. It

neither oscillator tone is present on reproduction of the record on tape I8, it is known that two operators were on duty, both head phone sets lating magnets 2i of recorder Il, the same as in will be evident that closure of either switch S1 or s switch Se will result in energization of the corresponding relay magnet, which will `in turn connect the corresponding earphone set across communication signal circuit I5, Il.

lhe stationary relay contacts Il and l5 are connected to communication signal circuit lead Il by circuit leads 5I and 1I, and as here shown, said leads contain circuit elements through which indication signal currents are introduced thereto. Thus, in the specific arrangement of Fig. l, circuit leads il and 5I contain the secondary windings 52 and I3 of coupling transformers T, which have their primary windings I4 and Il connected to the output terminals of generators il and Il, respectively. Generators Il and l1 may typically be vacuum tube oscillators of conventional'design. oscillators 56 and i1 will, however, preferably be designed to gencrate currents of sufiiciently diiferent frequencies as to be readily distinguishable. For instance, both may generate frequencies in the audio range, but the frequency of one may typically be twice the frequency of the other. Of course, any expedient other than the use of oscillators having diilerent frequencies may be employed for the purpose of generating two readily distinguishable curreut waves, the purpose of the generators 56 and II being simply to introduce to circuits III and II two currents which may be recorded by recorder I1, and which are readily distinguishable upon subsequent audible reproduction.

As previously explained, the contact arms 32 and 38 of relays R1 and Rz stand normally in contact with arms 3l and 35, respectively. At such time. the output currents delivered from oscillator l! and 51 are connected through circuits 50, ll and II, Il, respectively, across signal current circuit I5, Il, and hence ilow in the latter to recording magnets 2| of recorder I1 and are recorded on magnetic tape It. The oscillator currents from both oscillators 56 and 51 as well as any communication signal current delivered from radio receiver I3 will thus ilow in circuit I5, I6 and in magnets 2|. The record on tape I8 accordingly consists ot the communication signal, with the two oscillator waves superimposed thereon. Upon subsequent reproduction, the two oscillator waves will be distinguishable from the communication signal, being recognizable, for instance, as two tones of different pitches. The

^ presence of both tones of course indicates that neither head phone set was in use. If on reproduction. but one of the oscillator tones is heard, the meaning is that the corresponding head phone set was not in use, but that the other head phone set was in use. Thus it is known that but one operator was on duty, and it is known which head phone set (that of the pilot, or oi' the copilot or radio operator) was being used. And ii' imposed on both oscillator records.

Fig. l. However, the two oscillator tones are recorded by means of separate pairs oi' translating vmagnets Iii and 8l, the three pairs of translating magnets 2l, 80 and Il being spaced transversely of the record tape (see Fig. 3) so as to make three recordings on three adjacent, longitudinally extending lanes of the tape. In Fig. 2, circuit leads 50 and 5I, instead of being connected to communication signal circuit I5, I6, are connected to leads BI and M, going to one side of the windings of electromagnets 60 and BI, respectively. The other sides of the windings of said electromagnets B0 and BI are connected by leads 65 and $6 to the arms I2 and 33 of relays Rl and R2, respec tively. A

The oper tion of the system of Figs. 2 and 3 is the same that of Fig. 1, excepting only that oscillator output currents are delivered to circuits 63, and 8|, 86, to be recorded as separate records on the tape. rather than to the circuit I5, I6 to be recorded along with the communication signal, asin Fig. 1.

Fig. 4 is a stlllfurther modification, in which thetwo oscillator currents are recorded as separate records on laterally spaced lanes of the tape, the same as in Figs, 2 and 3, but in which the communication signal current, instead of being recorded as a third individual record, is super- Thus, as shown in Fig. 4, the circuit I5, I6 is connected by leads 10 and 1I across circuits 63, 65 and 64, G8. Accordingly, circuit 63, G5 and magnet B0 will carry the oscillator current from oscillator 56, as well as any communication signal` Y ing communication signals, as wellas the record r of an oscillator wave throughout all periods that the corresponding head phone set was not in use.

In all of the above described systems, reproduction of the record or records obtained as described enables accurate ascertainment oi' what communication signals were received by the aircraft throughout the flight, as well as ascertainment of whether the operators of the aircraft were properly listening in at all times, or during the reception of any particular communication. Besides the valuable information to be gathered from the record, for instance in the event of a mishap and the desire to ascertain if certain instructions were duly received, the positive check on the operators provided by the system is strongly conducive to proper attention to duty.

In the illustrative forms of the invention, the oscillator currents are recorded during periods of non-use of the earphones, stretches along the record devoid of the oscillator record denoting periods of use of the earphones. Of course, this relationship may be reversed; and whether the presence or absence of oscillator signal on the record tape -corresponds with use vof the -earto the output of the radio receiver. Thus the phgnes,..the record `asza whole may be regarded phones will remain "dead" if they are -not in phones.

.- tional earphone, thel forward wall .101 which this-switch device includes-.threepairs ofconrivet 98. Spring'inember 95 carries at its oppoopposed by inwardly facing contact 01 mounted 1 88. Elect-rical'connections 89 and |00 are made 35v spaced apart. `Inward pressure on the spring as arecord indicating periodsofuse -of the earproper position at the ears of the operator.

1 Figs. 8 and 9 show a modication. The re- Figs'.- 5,-,.6 and'l 7 showgan earphonedevice 5 ceiver case 80 is the same as in Figs. 5 and 6.4. equipped with an 'automatically actuated switch, Case 80 is enclosed by an exterior case |30 cornin accordance with the invention'. .Numeral 80 prising a peripheral. member |3 4and' a back designates generally the metal'case of` a.;conyen- .member |32. Back. 1me"x nber |32 has an annular' H 'ange |33 v'ricceiveii-- tightiy inside peripheral 1T02 designed? .10x-member |3| }andfabutting a rearwardly facing shoulderlli'on 00; a rubber washer'l31 `preferably'.,being placed between flange |33 and escuderias.,

'er'iph'eral'zmembe lhas. forwardiy'of `case a -bcrev |40 `which lidablyxreoevesun .outrdlyfxtending, annularV flangeV 14| on anear v pie'lilllngr lufthff `trjhlli11-"" ""annlll-lytacts 81 and '88 circulariy-spaoed about ring -i1 portion |43 slidablewithin-'reduced boreglMrL'Tlie (see'Fig. 7). The contact 88 of the iirst'fpair rearwardly'facing-'shoulderfatd45,betweenfbores vis mounted on a.Ictulductive arm 00 secured :to' 204| andlllgvserves-fa's'ia stop-tofoutward.-niovef ring 5l. Contact' 88 faces away flOm ring 84,' ment of Ithe" plunger.-Plunger fIIZ-'hasapertun in opposition to inwardly facing contact 81. gaat the:nf`, t admit goudwgveg, ,gni-has. i The latter` is mounted on one end of a flat spring mounted on `its inner 'lface'f |5'|. aroundaiertureg 92, secured at the center to ring 8l. as by means |50, a switch contact/,means asf which,is. prefere; of rivet 93. The other end of springl 82 carries 25 ably-and here showt-.8505. thesainenaturejas the outwardly facing Contact 88 0f the next Pair that iuustratedinFig--"z, andlistiierefore 'identi- 0f contacts' and opposed t0 Said Contact 8s is tied by corresponding'reference numerals.. 5v The.- .v a contact 81 carried by one end 0f 8419i Spring mountinglxringfuiin`fthis.=instanc 'secured to member es simuarto spme member 92. member the face islyandthespring;'membersepearing 95 beine mounted 0n me s* as by means 0f 3 the conti-icte-ai eomeadiacet auiiisuiauonrmg |60 secured to'thefront face ,oizca'se 80...;,1Whe'n the: earphonei'asf'- thus described iszpressed tof the 4, ear, the plunger |42" is depressedfior moyedainf.; wardly'relatiye to niern'beral'l arid-case 80,' then? 'spring arms carrying ftliecontacts v01 vheirigpi-e'- r' "vented from inwardmoyenienttby. th.- case 00. and

the contacts glaccordingly .closing against .them to complete 'the .circuit 'between connections. 99.

is formed with usual periorations tofperniitjentranceofjsound,waves, by rlvets to theuiront-,faoefd 1s g ing ring 84,' angins'ulatio ring] refer'ably. being-placed .beweem-ririgfl all-8|.'v Mounted 'on ring-luis v a. switc evice generaliyf designated by numeral' '86. i *its hexeffexnbodied,l

site end. outwardly facing contact 88, whichv is on vspring arm 91 secured to .ring 84 as by 'rivetsV to'members 90 and 91; respectively, as shown t in Fig. 6.,' .The contacts 'l'and 88 are normally contactarms carrying -the inwardly facing conand 'M as bfore completes the circuit from connection 88 to conv callyfeffectedwhen thetheearphone is pressed against-theear of the operator.

4- piece 'portion --li'having -lat the center an apertact 81rcauses contact to be made between the 40' It will benderstodd'fth'atth'e arawi',s and` several-pairs of contacts 01, 88., and therefore. l description a-fr mustrativp ses; anim and that various' changes in design.` structure and -ari rangement maybe made without departingrfrom 45 the sprlritan'd scope vof the invention or oftlief'" 'nection |00.V Such inward pressure is automati- Asishownyin Figs. 5;. and 6, the earphone case aprlgqgiW-s'.' v 801s' fsurrounded-ibyla soft rubber Jacket |02. l I v'- f ja system of the character described, tbev which'has't 'thefron't a' flexible Wan or em. combination off a circuit for communication sig` Y. .vv 50 nal currents,v an earphonel arranged to receive' tllf'gtgggmge Sgldtgaggll; signal currents from said'circui, and means conv 1 come-immediately 'adjacent the spring carrying, U t o )ed by msitmnmg Said earphone at *he ear `arms forj'the movable.. contacts 81.A Jacket |02 nat; opramr fof making a recoijd endizatingts vthecfperiphery.of .case 80 closely, except at p92 o s 0' 'uqe of smdearpmnethe bottom. where 'space'is provided for conduc`q55 In @System .of the character es crbedf he tors. and fits the back of the case closely except combnatmn of a' Cirmt for ommumcaton Sigfor an enlargement |05, designed to accommodate nal currents' .an A eau-hone al'nl'anged t0 'TeCeIVe earphone terminals |08, connections |01 leading Signal currents from Said circultf and means 60nfrom -the latter out an aperture |08 at the bottroued by Pressing. Said euphorie Heemst the ear torn, and connections |09 for-the other earphone 00 of an Operator fOr making a record indicating of the set leading out an aperture H0 at the periods 0f Se 0f Said eaphone. mp of the enlargement |05 3. In a system of the character described, the when theearphone is pressed against the ear combination of a circuit for communication sigor the operator', the flexible wan ma is demoted nel Currents. a phone arranged to receive signal inwardly, and depresses contacts 81 against con- 65 currents from said circuit, means for producing *acts n' thus dosing the circuit from connection an indication current whose flow is controlled in 0l t onnection |00'. The provision of the three accordance with use of the phone. and means for pair: gi contacts 01, 08 necessitates proper posimaklng a time record/9 la tl'ahng record me' 'Honing of 'the earphones on the head of the dum of said indication current inamanner to inwexet as otherwise au three pairs. contacts 70 dicate periods of use and non-11se of said ear- I will not be closed, and' the circuit will remain Phonegpe'n, The operator will know when the ear- 4. In a system of the character described, the phones are .properly positioned and all three pairs combination of a circuit for communication sigof contacts are closed by reason of the fact that nal currents, an earphone arranged to receive ,at suchtime'the' earphones become connected signal currents from'said circuit, means for proof signalicurrentsnnd a record ducing and recording an 'indicationfcurrenu and means controlled bypositioiiing saidz earphone at the ear of an'operator'or interrupting'recrdaltion of saidindicationcurrerit. '1V-' 'f 7- t 'l 5. lin-a systemr'of the" `haracter=desribed, fthe combination ldira circuit l'for'communnication signal curre'nts,- -an'earphone arrar'ige'iL to`- @receive signallcurrents irox'nisaid circuit',`'and'mea` ns for making on atraveling record medium of a record indicating'periods "l 6. .In a system or the character describedgiftnew.. combination of acircuit-fior'A communication? sig-- nal currentafan-earphone -arranged'lt receive signal-currentsvirom-fsaid circuit.means' for'pr l5 ducing anindi'cationcurrent; and means forcon y tinuously recording" communication sig'nal -v curlrents, and for recording said indicaton."currents during times indicating periods .offuse of said ear- -.1 phone. 20

'IJIn a system :of the character described, the# combinationof 'a circuit for communication signal v currents. an earphone-arranged ltoreceive-.signal lf' e' currents from said circult,means for producingfan indication current. and 'means .for continuously., recording communicationzsignal currents, and .-for recording said indicationcurrents duringperiods of non-use of saidiearphone. .l

8. In a system of the character described. the combination of acircuit for communication signal 3o currents, an earphone arrangedfto receivesignal currents trom said circuit.y means vfor producing. an-f; indication currentrand means for making fa composite record ot communication signal currents, and o f said indication current during. times such` 35 as willindicate periods of use oiisaidiearphonef.

9. In a .system ofrthecharacter described-the combination or a circuit for communication; sig nal currents, -an earphone arranged to receive. signal currentsirom said circuit, means for profducing an indication current,and means for malring a composite recordof communication signal. currents, and of said indication current during times of non-use of said earphone.

10. In a system of the character described.. the combination of a circuit for communication signal currents, a plurality of earphone devices arranged to receive signal currents from said circuit, means for producing a corresponding plurality of indication currents of different characteristics, and means for continuously recording communication signal currents, and for recording said indication currents during times indicating periods of use of the respective earphone devices.

11. In a system or the character described. the combination of a circuit for 4c :ommunicatlion'signal means from saidvrecorder.'

13. In-afsyste'm of;t-he character to receive slgnalcurrents from-said.circuit,means for producing a corresponding plurality of indica tion currents fof :diierent frequency .characteris tics,'"'and means '-for continuously :recording coma... municationsignal currents, and for recording said indication `currents during. timesf dndcating- .pe riod'sutuse oiftne irespective earphone devices.

S 12x-Init. system=of :the-characterdescribed,the combinationo'f acircuit forfcommunication Signal currents. an earphoneacurrent..producingimeans for producing an indicatidncurrenq, arrecgrder for recording electrical currents, means normally connectingfsaidi currentproduclng means-tolsai recorder. and means automaticalivoperablewhile 1 said earphoneisipositionedgat the-ear-of an oper-- ator '-for 4disconnectingsaid current: producing described, the i combinationioi a circuit for communicationfsig-V nal currents, an eanphone device. a switchen-said earphone' de't'ice" automatically. closed when. said earphone deviceisspressed to the ear of an op er rator, asource of electrical current of predeteri mined i characteristics, a recorder for electricalcurrents, electric ircuiting normally. -connecting said source-of .currentof predetermined characteristi'cs tosaidrecorder. =and .circuiting operai-r lingwhen said earphoneswitch is closedto. connect said -earphone :device-:to said. communica tion signaicircuit and Ato disconnect; said. source of current from saidnecorden.. .f 1-:f i Y Malin a system of; the fcharactere described, the,

combination or 'a circuit for` communication signal currents. an earphone device, a switch on said earphone device automatically closed when said earphone device is pressed.l totheear of an oper- 4 ator, a source ofnelectricalcurrent of Apredeterf.

-. mined characteristics, arecorder for electrical currents receiving electric currents iromsaid conm.. i municationv'signal circuitfelectric circuitingnormany-.connecting said source oiecurrent ot predeter'mined characteristicsxto said: recorder; .and circuiting operating when said earphone switch is closed to connect said earphone device vto said communication signal circuit and to disconnect said source of 'current from said recorder. i5. In combination with an earphone device having a case, a switch mounted on said case, and a jacket for said case including a centrally perfor-ated flexible depressible wall at the inner side of said case forming an ear piece adapted to be engaged and depressed by the ear oi a listener and to operate said switch means by such depression.

HERMAN S. HELLER.

CEHTFI CATE 0F CORRECTI 0N Petegem. 2, 5142,66?. February i 29;., 19%.',

HERMAN s. KELLER.

It is hereby certified that error appears in the printe'@ sgietviific'tion ofthe above numbered lpatent requiring correction as follows: Pageh, first.

' column, line 9, claim 5, for "of" read both-fand thee-ehe said Letters Patent should be read with this correction therein' thi-tithe seme IpeVyHQOIif-" fom to the record of the case 1n the Patent off-1o.

Signed avnd sealed this 16th dayof May, A. D' 3.914141 Leslie Frazer (Seal) Acting Commissioner of Patets. 

